WO2019086275A1

WO2019086275A1 - Skin cleansing composition and method of use

Info

Publication number: WO2019086275A1
Application number: PCT/EP2018/078742
Authority: WO
Inventors: Nicholas John Ainger; Wei Gao; Adam Peter Jarvis; Kinjalbahen JOSHI; Curtis Schwartz; Neil Scott Shaw; Inna Shulman; Pierre Starck; Sally Elizabeth WOOD; Fanwen Zeng
Original assignee: Unilever Plc; Unilever N.V.; Conopco, Inc., D/B/A Unilever
Priority date: 2017-11-03
Filing date: 2018-10-19
Publication date: 2019-05-09

Abstract

An aqueous skin cleansing composition, comprises: (I) a cleansing surfactant selected from the group consisting of anionic surfactant, cationic, zwitterionic or amphoteric surfactant and nonionic surfactant; (II) a skin benefit agent, (III) an anti-settling, thickening polymer, wherein the anti-settling, thickening polymer, comprises: (a) 40 to 74.5 wt% of structural units of C1-4 alkyl acrylate; (b) 20 to 50 wt% of structural units of methacrylic acid; (c) 0.2 to < 5 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS); (d) 5 to 25 wt% of structural units of a specialized associated monomer having the following structure wherein R1 is a linear saturated C10-24 alkyl group; wherein R2 is a hydrogen or a methyl group (preferably, wherein R2 is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R1 is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R1 is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R1 is, respectively, a linear saturated C12 and a linear saturated C18 alkyl group; or (iii) two specialized associated monomers, wherein R1 is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; (e) 0 to 1 wt% of structural units of acrylic acid; and (f) 0 to 2 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer or chain transfer agent; and wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt% of the anti-settling, thickening polymer; and a method of treating skin comprising the step of applying to the skin such a composition.

Description

SKIN CLEANSING COMPOSITION AND METHOD OF USE

Field of the Invention

The present invention relates to aqueous cleansing compositions, containing a hydrophobically modified alkali swellable emulsion (HASE) polymer as anti-settling thickening polymer, suitable for topical application for cleansing the skin. The invention further relates to a method of treating skin by means of such compositions.

Background and Prior Art

Cleansing compositions having beneficial ingredients suspended therein are desirable to the consumer seeking to deliver benefit to surfaces, such as the body and skin. Such formulations have suspended materials that typically impart, or contribute to, certain user benefits, including: visual product aesthetics, various active effects and encapsulation/release of separate phases during use.

To be acceptable to consumers, such aqueous compositions desirably exhibit both an appealing look and feel. Such suspensions, however, in complex aqueous formulations for rinse-off applications in home and personal care applications present significant challenges.

Notwithstanding, the benefits associated with the incorporation of cosmetic ingredients suspended in aqueous compositions, their incorporation creates a variety of complications. For example, cosmetic ingredients typically have a density disparate from the continuous phase of the composition. This density mismatch can lead to compositional instability. In systems containing insoluble materials with a density less than that of the continuous phase, the cosmetic ingredients tend to float to the top surface of the continuous phase (i.e., creaming). In systems containing insoluble materials with a density greater than that of the continuous phase, the insoluble materials tend to sink to the bottom of the continuous phase (i.e., settling). Commercial products have utilized cationic polymers as structurants. For instance, U.S. Patent 7,541 ,320 (Unilever) discloses a cationically modified cellulose in a cleansing system that includes alkyl ether sulfate (3 EO), cocoamidopropylbetaine and cocoamidopropylhydroxysultaine, and as a conditioning active a non-volatile silicone. U.S. Patent 4,298,494 (Lever Brothers) reports use of a cationic derivative of polygalactomannan gum to stabilize a sodium alkyl sulfate and alkyl ether sulfate surfactant system. Another group of commercially popular structurants are the acrylic polymers, particularly those known as Carbomers. For example, U.S. Patent 5,543,074 (Chesebrough-Ponds) and U.S. Patent 5,977,039 (Helene Curtis) regulate silicone deposition through use of crosslinked polymers of acrylic acid, commercially available under the trademark Carbopol(R). U.S. Patent 6,001 ,344 (Unilever) utilizes structurant combinations of xanthan gum and Carbopol(R) for stabilizing liquid cleansing compositions. U.S. Patent 6,906,016 (Unilever) reports liquid cleansers structured with soluble and water swellable starches combined with linear Cs-Ci3 fatty acids. U.S. Patent Application Publication 2010/0009891 (Unilever) reports personal care liquid compositions formulated with a bacterially produced microfibrous cellulose as a suspending system. An approach to the suspending of insoluble materials in an aqueous cleansing formulation is disclosed in United States Patent No. 8,642,056 to Souzy, et al. Souzy, et al. disclose a method for thickening a formulation, comprising contacting a cosmetic formulation with a direct aqueous emulsion of a polymer, followed by regulation of the pH to a value between 5 and 7, thereby forming a thickened formulation, wherein the emulsion is free from surfactants and organic solvents other than water and the polymer consists, expressed as a % by weight of each of the monomers therein, of: a) 20% to 60% by weight of methacrylic acid and/or acrylic acid, where the % by weight of acrylic acid, if present, compared to the total weight of acrylic acid and methacrylic acid is at least 50%, b) 40% to 80% by weight of at least one monomer chosen from among ethyl acrylate, butyl acrylate, and methyl methacrylate, c) 0.5% to 25% by weight of a monomer comprising a hydrophobic group, d) 0.05% to 22% by weight of 2-acrylamido-2-methylpropane sulfonic acid, and e) 0 to 1 % by weight of at least one cross-linked monomer, wherein the monomer comprising a hydrophobic group has the general formula

R-(OE)_m-(OP)_n-R',

m and n are integers of less than or equal to 150, at least one of which is non-zero, OE and OP are respectively ethylene oxide and propylene oxide, R is a polymerizable group selected from the groups consisting of methacrylate and methacrylurethane groups, R' is a hydrophobic group having at least 6 and at most 36 carbon atoms. Another approach to the suspending of insoluble materials in an aqueous cleansing formulation is disclosed in United States Patent No. 6,106,816 to Hitchen. Hitchen discloses an aqueous conditioning shampoo composition comprising, in addition to water: (a) from 2 to 40% by weight of surfactant selected from the group consisting of anionic, nonionic and amphoteric surfactants, and mixtures thereof; (b) from 0.01 to 10% by weight of insoluble, non-volatile silicone which conditions hair; (c) from 0.01 to 3% by weight of titanium dioxide coated mica particles dispersed in the shampoo matrix; and (d) from 0.2 to 3% by weight of a crosslinked acrylic acid polymer for suspending the dispersed titanium dioxide coated mica particles and preventing them from settling in the composition as well as the insoluble, non-volatile silicone conditioning agent from creaming to the top of the composition on standing.

Additionally, conventional hydrophobically modified alkali swellable emulsions (HASE) polymers, used for anti-settling and thickening applications, can have the effect of reducing the deposition of the included cosmetic ingredients (for example; silicone) to the skin. Aqueous compositions comprising other available thickening polymers are able to deliver good deposition of cosmetic ingredients, but have compromised visual characteristics.

EP2933280 discloses aqueous shampoo compositions comprising HASE copolymers which comprise a) 10 to 80 percent by weight of methacrylic acid and, optionally, of acrylic acid; b)15 to 80 percent by weight of at least one non-ionic vinyl monomer; c) 0.05 to 9.5 percent by weight of 2-acrylamido-2-methylpropane sulfonic acid or a salt thereof; d) 0.5 to 30 percent by weight of at least one monomer containing at least one hydrophobic group; and e) 0.01 to 5 percent by weight of at least one crosslinking monomer. The copolymers are said to be useful for thickening personal care or cosmetic formulations in acidic conditions.

Accordingly, there is a need for an aqueous skin cleansing composition that provides superior visual characteristics, without impairing other product attributes such as stability and benefit performance.

It is well known that the addition of thickening polymers causes a reduction in the transparency of a composition to which they are added. This can be demonstrated by starting with a highly transparent simple aqueous composition, comprising for example, surfactant and water, and then adding a thickening polymer. The resultant reduction in transparency of the composition can be clearly observed. However, we have now surprisingly found that the high visual transparency of the starting aqueous composition is preserved upon addition of the specific anti-settling thickening polymer, herein defined. The impact of this high transparency has a positive visual effect even after insoluble ingredients, such as mica, titanium dioxide or silicone are subsequently added to the composition. Whilst no longer transparent, the resulting composition has an improved visual appearance that is appealing for the consumer. We believe that the polymer for use in the compositions of the invention prevents aggregation of suspended material, which results in reduced turbidity and higher reflection of light from the surfaces of the suspended material, thus resulting in the improved visual appearance.

We have now found that an aqueous composition comprising a specific anti-settling thickening polymer, herein defined, provides superior visual properties, whilst maintaining good levels of deposition of a benefit agent to the body (skin) as well as stability.

Definition of the Invention

A first aspect of the invention provides an aqueous skin cleansing composition, which comprises:

(I) a cleansing surfactant selected from the group consisting of anionic surfactant, cationic, zwitterionic or amphoteric surfactant and nonionic surfactant;

(II) a skin benefit agent,

(III) an anti-settling, thickening polymer,

wherein the anti-settling, thickening polymer, comprises:

(a) 40 to 74.5 wt% of structural units of C1-4 alkyl acrylate;

(b) 20 to 50 wt% of structural units of methacrylic acid;

(c) 0.2 to < 5 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS);

(d) 5 to 25 wt% of structural units of a specialized associated monomer having the following structure

wherein R¹ is a linear saturated C10-24 alkyl group; wherein R² is a hydrogen or a methyl group (preferably, wherein R² is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C12 and a linear saturated C18 alkyl group; or (iii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group;

(e) 0 to 1 wt% of structural units of acrylic acid; and

(f ) 0 to 2 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer or chain transfer agent; and

wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt% of the anti-settling, thickening polymer. A second aspect of the invention provides a method of treating skin comprising the step of applying to the skin a composition of the first aspect of the invention.

The method of the invention preferably further comprises the additional step of rinsing the skin with water.

General Description of the Invention

The aqueous skin cleansing composition of the present invention contains an anti-settling thickening polymer, for use in the cleansing of skin.

The Anti-Settling Thickening Polymer The anti-settling, thickening polymer for use in the aqueous compositions of the invention, comprises: (a) 40 to 74.5 wt% (preferably, 45 to 69.5 wt%; more preferably, 50 to 65 wt%; most preferably, 52 to 60 wt%) of structural units of C1-4 alkyl acrylate (preferably, C2-4 alkyl acrylate; more preferably, C2-3 alkyl acrylate; most preferably, ethyl acrylate); (b) 20 to 50 wt% (preferably, 25 to 45 wt%; more preferably, 25 to 40 wt%; most preferably, 30 to 35 wt%) of structural units of methacrylic acid; (c) 0.2 to < 5 wt% (preferably, 0.5 to 3 wt%; more preferably, 0.75 to 2.0 wt%; most preferably, 0.75 to 1 .5 wt%) of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS); (d) 5 to 25 wt% (preferably, 7.5 to 22.5 wt%; more preferably, 10 to 20 wt%; most preferably, 12.5 to 18 wt%) of structural units of a specialized associated monomer having the following structure (formula 1 ):-

wherein R¹ is a linear saturated C10-24 alkyl group; wherein R² is a hydrogen or a methyl group (preferably, wherein R² is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated Cis alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C12 and a linear saturated Cis alkyl group; or (iii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; (e) 0 to 1 wt% (preferably, 0 to 0.1 wt%; more preferably, 0 to 0.01 wt%; most preferably, 0) of structural units of acrylic acid; and (f) 0 to 2 wt% (preferably, 0 to 0.1 wt%; more preferably, 0 to 0.001 wt%; most preferably, 0 wt%) of structural units of multi-ethylenically unsaturated crosslinking monomer and chain transfer agent; wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt% of the anti-settling, thickening polymer. Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention, comprises: (a) 50 to 65 wt% of structural units of ethyl acrylate; (b) 25 to 40 wt% of structural units of methacrylic acid; (c) 0.75 to 2.0 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS); (d) 10 to 20 wt% of structural units of the specialized associated monomer; (e) 0 to 0.1 wt% of structural units of acrylic acid; and (f) 0 to 0.1 wt% (preferably, 0 to 0.001 wt%; more preferably, 0 wt%) of structural units of multi-ethylenically unsaturated crosslinking monomer and chain transfer agent; wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt% anti-settling, thickening polymer.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention has a weight average molecular weight of 5,000,000 to 400,000,000 Daltons. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention has a weight average molecular weight of 25,000,000 to 300,000,000 Daltons. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention has a weight average molecular weight of 175,000,000 to 275,000,000 Daltons.

In reference to the anti-settling thickening polymer the weight average molecular weight refers to the weight average molecular weight as measured using asymmetric flow field flow fractionation (AF4) with inline Multi-Angle Light Scattering (MALS) and differential Refractive Index (Rl) detections. The AF4 instrument used consisted of an Eclipse™ DualTec™ separation system (from Wyatt Technology Corp.) that was coupled in series to an 18 angle multi-angle light scattering (MALS) detector (DAWN HELOS II; from Wyatt Technology Corp.) and a differential refractometer (Rl) (Optilab rEX; from Wyatt Technology Corp.). Flows through the AF4 instrument were provided using an Agilent Technologies 1200 series isocratic pump equipped with a micro-vacuum degasser. All injections were performed with an auto sampler (Agilent Technologies 1200 series). Data from the AF4 instrument were collected and processed using Astra software version 7.0.1 .23 (from Wyatt Technology Corp.). Samples were prepared at a concentration of 1 mg/mL in 20 mM ammonium acetate solution at pH 10 (filtered with a 1.2 m pore nylon membrane). Samples (25 μί) were injected into the standard separation channel system (25 cm long and a width dimension starting at 2.15 cm and reducing to 0.3 cm over the length) with a channel thickness of 350 μηη and equipped with a 10 kDA cutof regenerated cellulose ultrafiltration membrane (Wyatt Technology). The mobile phase used for the AF4 analysis was 20 mM ammonium acetate solution at pH 10. Separation was performed with an applied channel flow of 1 mL/min. The sample was introduced to the channel with a focus flow at 1.7 mL/min for 3 minutes. The elution flow as then started at 0.5 mL/min for 3 minutes and then followed by a linearly decreasing cross flow gradient (from 0.5 mL/min to 0.05 mL/min over 12 minutes), then a hold at 0.05 mL/min for another 5 minutes. The average molecular weight was calculated using Astra software version 7.0.1 .23 after subtracting a blank injection with a refractive index increment (dn/dc) of 0.190 mL/g for all calculation with Berry model 2^nd order fit. Molecular weights are reported herein in units of Daltons.

Preferably, the structural units of C1-4 alkyl acrylate in the anti-settling, thickening polymer for use in the aqueous compositions of the invention are structural units of C2-4 alkyl acrylate. More preferably, the structural units of C1-4 alkyl acrylate in the anti-settling, thickening polymer for use in the aqueous compositions of the invention are structural units of C2-3 alkyl acrylate. Most preferably, the structural units of C1-4 alkyl acrylate in the anti-settling, thickening polymer for use in the aqueous compositions of the invention are structural units of ethyl acrylate.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 40 to 74.5 wt% of structural units of C1-4 alkyl acrylate (preferably, C2- 4 alkyl acrylate; more preferably, C2-3 alkyl acrylate; most preferably, ethyl acrylate). More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 45 to 69.5 wt% of structural units of C1-4 alkyl acrylate (preferably, C2- 4 alkyl acrylate; more preferably, C2-3 alkyl acrylate; most preferably, ethyl acrylate). Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 50 to 65 wt% of structural units of C1-4 alkyl acrylate (preferably, C2-4 alkyl acrylate; more preferably, C2-3 alkyl acrylate; most preferably, ethyl acrylate). Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 52 to 60 wt% of structural units of C1-4 alkyl acrylate (preferably, C2-4 alkyl acrylate; more preferably, C2-3 alkyl acrylate; most preferably, ethyl acrylate).

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 20 to 50 wt% of structural units of methacrylic acid. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 25 to 45 wt% of structural units of methacrylic acid. Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 25 to 40 wt% of structural units of methacrylic acid. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 30 to 35 wt% of structural units of methacrylic acid.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0.2 to < 5 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS). More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0.5 to 3 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS). Even more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0.5 to 1.5 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS). Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0.5 to 1 .0, of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS).

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 5 to 25 wt% of structural units of a specialized associated monomer having the following structure

wherein R¹ is a linear saturated C10-24 alkyl group; wherein R² is a hydrogen or a methyl group (preferably, wherein R² is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C12 and a linear saturated C18 alkyl group; or (iii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 7.5 to 22.5 wt% of structural units of a specialized associated monomer having the following structure

wherein R¹ is a linear saturated C10-24 alkyl group; wherein R² is a hydrogen or a methyl group (preferably, wherein R² is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C12 and a linear saturated C18 alkyl group; or (iii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group. Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 10 to 20 wt% of structural units of a specialized associated monomer having the following structure

wherein R¹ is a linear saturated C10-24 alkyl group; wherein R² is a hydrogen or a methyl group (preferably, wherein R² is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C12 and a linear saturated C18 alkyl group; or (iii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 12.5 to 18 wt% of structural units of a specialized associated monomer having the following structure

wherein R¹ is a linear saturated C10-24 alkyl group; wherein R² is a hydrogen or a methyl group (preferably, wherein R² is a methyl group); and wherein n is an average of 20 to 28; with the proviso that the structural units of the specialized associated monomer (d) are derived from one of (i) a single specialized associated monomer (preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group; more preferably, a single specialized associated monomer wherein R¹ is selected from the group consisting of a linear saturated C12 alkyl group and a linear saturated C18 alkyl group); (ii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C12 and a linear saturated C18 alkyl group; or (iii) two specialized associated monomers, wherein R¹ is, respectively, a linear saturated C18 alkyl group and a linear saturated C22 alkyl group.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes 0 to 1 wt% of structural units of acrylic acid. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes 0 to 0.1 wt% of structural units of acrylic acid. Still more preferably, anti-settling, thickening polymer for use in the aqueous compositions of the invention contains 0 to 0.01 wt% of structural units of acrylic acid. Yet still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than the detectable limit of structural units of acrylic acid. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention contains 0 wt% structural units of acrylic acid. Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0 to 2 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer and chain transfer agent. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0 to 0.1 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer and chain transfer agent. Still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention comprises 0 to 0.001 wt% of structural units of multi- ethylenically unsaturated crosslinking monomer and chain transfer agent. Yet still more preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than the detectable limit of structural units of multi-ethylenically unsaturated crosslinking monomer and chain transfer agent. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention contains 0 wt% structural units of multi-ethylenically unsaturated crosslinking monomer and chain transfer agent. Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than 0.001 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than 0.0001 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer. Still more preferably, anti-settling, thickening polymer for use in the aqueous compositions of the invention contains less than the detectable limit of structural units of multi-ethylenically unsaturated crosslinking monomer. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes 0 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than 0.1 wt% of structural units of chain transfer agent. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than 0.001 wt% of structural units of chain transfer agent. Still more preferably, anti-settling, thickening polymer for use in the aqueous compositions of the invention contains less than the detectable limit of structural units of chain transfer agent. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes 0 wt% of structural units of chain transfer agent.

Preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than 0.001 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer and less than 0.1 wt% of structural units of chain transfer agent. More preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes less than 0.0001 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer and less than 0.01 wt% of structural units of chain transfer agent. Still more preferably, anti-settling, thickening polymerfor use in the aqueous compositions of the invention contains less than the detectable limit of structural units of multi-ethylenically unsaturated crosslinking monomer and less than the detectable limit of structural units of chain transfer agent. Most preferably, the anti-settling, thickening polymer for use in the aqueous compositions of the invention includes 0 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer and includes 0 wt% of structural units of chain transfer agents. One of ordinary skill in the art will know to select appropriate multi-ethylenically unsaturated crosslinking monomers to provide any structural units of multi-ethylenically unsaturated crosslinking monomer in the anti-settling, thickening polymer for use in the aqueous compositions of the invention. Structural units of multi-ethylenically unsaturated crosslinking monomer may include for example those derived from polyunsaturated monomer components including, polyunsaturated aromatic monomers (e.g., divinyl benzene, divinyl naphthalene, trivinyl benzene); polyunsaturated alicyclic monomers (e.g., 1 ,2,4-trivinylcyclohexane); difunctional esters of phthalic acid (e.g., diallyl phthalate); polyunsaturated aliphatic monomers (e.g., isoprene, butadiene, 1 ,5-hexadiene, 1 ,5,9- decatriene, 1 ,9-decadiene, 1 ,5-heptadiene); polyalkenyl ethers (e.g., trially pentaerythritol, diallyl pentaerythritol, diallyl sucrose, octaally sucrose, trimethylolpropane dially ether); polyunsaturated esters of polyalcohols or polyacids (e.g., 1 ,6-hexanediol di(meth)acrylate, tetramethylene tri(meth)acrylate, allyl acrylate, diallyl itaconate, diallyl fumarate, diallyl maleate, trimethylolpropane tri(meth)acrylate, trimethylolpropane di(meth)acrylate, polyethylene glycol di(meth)acrylate); alkylene bisacrylamides (e.g., methylene bisacrylamide, propylene bisacrylamide); hydroxy and carboxy derivatives of methylene bis-acrylamide (e.g., Ν,Ν'-bismethylol methylene bisacrylamide); polyethyleneglycol di(meth)acrylates (e.g., ethyleneglycol di(meth)acrylate, diethyleneglycol di(meth)acrylate, triethyleneglycol di(meth)acrylate); polyunsaturated silanes (e.g., dimethyldivinylsilane, methyltrivinylsilane, allyldimethylvinylsilane, diallydimethylsilane, tetravinylsilane); polyunsaturated stannanes (e.g., tetraallyl tin, diallyldimethyl tin) and the like.

One of ordinary skill in the art will know to select appropriate chain transfer agents to provide any structural units of chain transfer agents in the anti-settling, thickening polymer for use in the aqueous compositions of the invention. Structural units of chain transfer agents may monomer include those derived from a variety of thio and disulfide containing compounds (e.g., CMS alkyl mercaptans, mercaptocarboxylic acids, mercaptocarboxylic esters, thioesters, CMS alkyl disulfides, aryldisulfides, polyfunctional thiols); phosphites and hypophosphites; haloalkyl compounds (e.g., carbon tetrachloride, bromotrichloromethane) and unsaturated chain transfer agents (e.g., alpha-methylstyrene).

Preferably, the composition of the present invention, includes from 0.05 to 4 wt% of the anti-settling, thickening polymer more preferably from 0.05 to 3 wt%, still more preferably from 0.1 to 1 wt% and most preferably from 0.2 to 0.8 wt% by weight of total composition.

Surfactants

Surfactants are an essential component of the inventive cleansing composition. They are compounds that have hydrophobic and hydrophilic portions that act to reduce the surface tension of the aqueous solutions they are dissolved in. Useful surfactants can include anionic, nonionic, amphoteric, and cationic surfactants, and blends thereof.

Anionic Surfactants

The cleansing composition of the present invention contains one or more anionic detergents. Anionic surfactants are preferably used at levels as low as 1 or 4, 8 or 12% by wt. and at levels as high as 16, 20 or 25% by wt.

Generally, the pH of the composition is preferably in the range of from 3.5 to 10, more preferably from 4 to 9.5. The composition of the invention may preferably be a body wash composition with a neutral to slightly acidic pH i.e. that the maximum pH is 7.5, preferably 6.8 or more preferably 6.5. The minimum pH is preferably 3.5, more preferably 4.5 and most preferably 5.5. Particularly preferred ranges are from 3.5 to 7 and from 4.5 to 6.8.

Alternatively, the composition of the invention may preferably be a liquid soap composition, with a maximum pH of 10, preferably 9.5 or more preferably 9. The minimum pH is preferably 7.5, more preferably 8.0 and most preferably 8.5. Particularly preferred ranges are from 7.5 to 10 and from 8.5 to 9.5.

The anionic detergent active which may be used in the invention may be aliphatic sulfonates, such as a primary alkane (e.g., C8-C22) sulfonate, primary alkane (e.g., C8- C22) disulfonate, C8-C22 alkene sulfonate, C8-C22 hydroxyalkane sulfonate or alkyl glyceryl ether sulfonate (AGS); or aromatic sulfonates such as alkyl benzene sulfonate.

The anionic may also be an alkyl sulfate (e.g., C12-C18 alkyl sulfate) or alkyl ether sulfate (including alkyl glyceryl ether sulfates). Among the alkyl ether sulfates are those having the formula: RO(CH2CH20)_nS03M wherein R is an alkyl or alkenyl having 8 to 18 carbons, preferably 12 to 18 carbons, n has an average value of greater than 1.0, preferably greater than 3; and M is a solubilizing cation such as sodium, potassium, ammonium or substituted ammonium. Ammonium and sodium lauryl ether sulfates are preferred.

The anionic may also be alkyl sulfosuccinates (including mono- and dialkyl, e.g., C6-C22 sulfosuccinates); alkyl and acyl taurates, alkyl and acyl sarcosinates, sulfoacetates, C8-C22 alkyl phosphates and phosphates, alkyl phosphate esters and alkoxyl alkyl phosphate esters, acyl lactates, C8-C22 monoalkyl succinates and maleates, sulphoacetates, alkyl glucosides and acyl isethionates, acyl glycinates and acyl glutamates, alkyl carboxylates, and the like.

Sulfosuccinates may be monoalkyl sulfosuccinates having the formula: R⁴02CCH₂CH(S0₃M)C02M; and amide-MEA sulfosuccinates of the formula; R⁴CONHCH₂CH202CCH2CH(S0₃M)C02M wherein R⁴ ranges from C8-C22 alkyl and M is a solubilizing cation. Sarcosinates are generally indicated by the formula: R¹CON(CH3)CH2C02M, wherein R¹ ranges from C8-C20 alkyl and M is a solubilizing cation.

Taurates are generally identified by formula: R²CONR³CH2CH2S03M wherein R² ranges from C8-C20 alkyl, R³ ranges from C1 -C4 alkyl and M is a solubilizing cation.

The inventive cleansing composition may contain C8-C18 acyl isethionates. These esters are prepared by reaction between alkali metal isethionate with mixed aliphatic fatty acids having from 6 to 18 carbon atoms and an iodine value of less than 20. At least 75% of the mixed fatty acids have from 12 to 18 carbon atoms and up to 25% have from 6 to 10 carbon atoms.

The acyl isethionate may be an alkoxylated isethionate such as is described in llardi et al., U.S. Pat. No. 5,393,466, titled "Fatty Acid Esters of Polyalkoxylated isethonic acid; issued Feb. 28, 1995; hereby incorporated by reference. This compound has the general formula: RC-0(0)-C(X)H-C(Y)H2-(OCH-CH₂)m-S0₃M⁺ wherein R is an alkyl group having 8 to 18 carbons, m is an integer from 1 to 4, X and Y are hydrogen or an alkyl group having 1 to 4 carbons and l\C is a monovalent cation such as, for example, sodium, potassium or ammonium.

Amphoteric Surfactants

One or more amphoteric surfactants are used in this invention. Amphoteric surfactants are preferably used at levels as low as 2, 4, or 6% by wt. and at levels as high as 12, 16 or 20% by wt. Such surfactants include at least one acid group. This may be a carboxylic or a sulphonic acid group. They include quaternary nitrogen and therefore are quaternary amido acids.

They should generally include an alkyl or alkenyl group of 7 to 18 carbon atoms. They will usually comply with an overall structural formula: R¹-[-C(0)-NH(CH₂)n-]m-N⁺-(R²)(R³)X-Y where R¹ is alkyl or alkenyl of 7 to 18 carbon atoms; R² and R³ are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms; n is 2 to 4; m is 0 to 1 ; X is alkylene of 1 to 3 carbon atoms optionally substituted with hydroxyl, and Y is -CO2- or -SO3 -. Suitable amphoteric surfactants within the above general formula include simple betaines of formula: R¹-N⁺-(R²)(R³)CH₂C0₂- and amido betaines of formula: R¹-CONH(CH₂)_n-N⁺- (R²)(R³)CH2CC>2- where n is 2 or 3. In both formulae R¹, R² and R³ are as defined previously. R¹ may in particular be a mixture of C12 and C14 alkyl groups derived from coconut oil so that at least half, preferably at least three quarters of the groups R¹ have 10 to 14 carbon atoms. R² and R³ are preferably methyl.

A further possibility is that the amphoteric detergent is a sulphobetaine of formula:

R¹-N⁺-(R²)(R³)(CH₂)₃S0³- or R¹CONH(CH₂)m-N⁺-(R²)(R³)(CH₂)3S03- where m is 2 or 3, or variants of these in which (CH₂)₃ S0₃ ^" is replaced by -CH₂C(OH)(H)CH₂S0₃ ^" In these formulae R¹, R² and R³ are as discussed previously.

Amphoacetates and diamphoacetates are also intended to be covered in possible zwitterionic and/or amphoteric compounds which may be used such as e.g., sodium lauroamphoacetate, sodium cocoamphoacetate, and blends thereof, and the like. The combination of total non-soap anionic, nonionic, amphoteric surfactants and polymeric dispersion stabilizing agents(s) (discussed below) should preferably be about 5 to 30% by wt. of the composition. Nonionic Surfactants

One or more nonionic surfactants may be used in the cleansing composition of the present invention.

Nonionic surfactants are preferably used at levels as low as 0.5, 1 , 1 .5 or 2% by wt. and at levels as high as 6, 8, 10 or 12% by wt. The nonionics which may be used include in particular the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols, acids, amides or alkylphenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionic detergent compounds are alkyl (C6 C22) phenols ethylene oxide condensates, the condensation products of aliphatic (C8-C18) primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulphoxide, and the like. Preferred nonionic surfactants include fatty acid/alcohol ethoxylates having the following structures

a) HOCH2(CH₂)n(CH2CH₂0)xH or

b) HOOC(CH2)m(CH2CH20)yH; where m, n are independently <18; and x, y are

independently >1. preferably m, n are independently 6 to 18; x, y are independently 1 to 30;

c) HOOC(CH₂)i-CH=CH (CH2)k(CH₂CH₂0)zH; where i, k are independently 5 to 15; and z is independently 5 to 50. Preferably i, k are independently 6 to 12; and z is independently 15 to 35.

The nonionic may also include a sugar amide, such as a polysaccharide amide. Specifically, the surfactant may be one of the lactobionamides described in U.S. Pat. No. 5,389,279 to Au et al. titled "Compositions Comprising Nonionic Glycolipid Surfactants issued Feb. 14, 1995; which is hereby incorporated by reference or it may be one of the sugar amides described in U.S. Pat. No. 5,009,814 to Kelkenberg, titled "Use of N-Poly Hydroxyalkyl Fatty Acid Amides as Thickening Agents for Liquid Aqueous Surfactant Systems" issued Apr. 23, 1991 ; hereby incorporated into the subject application by reference. The Skin Benefit Agent

The composition of the invention comprises a skin benefit agent. The skin benefit agent is preferably selected from optical and sensory modifiers (e.g. exfoliants), emollients, antiacne actives, antimicrobial and antifungal actives, antiwrinkle and anti-skin atrophy actives, skin barrier repair actives, artificial tanning actives, skin lightening actives, sunscreen actives, anti-itch ingredients, fragrance, moisturizers (e.g. occlusive like petroleum jelly; or non-occlusive like glycerin) optical modifiers and mixtures thereof.

Cationic Skin Conditioning Agents

A useful component in compositions according to the invention is a cationic skin feel agent or polymer, such as for example cationic celluloses. Cationic polymers are preferably used at levels as low as about 0.1 to 2% up to levels as high as the solubility limit of the specific polymer, or preferably up to about 4 to 5% by wt, provided that the solubility limit of the particular cationic polymer or blend thereof is not exceeded. Cationic cellulose is available from Amerchol Corp. (Edison, N.J., USA) in their Polymer JR (trade mark) and LR (trade mark) series of polymers, as salts of hydroxyethyl io cellulose reacted with trimethyl ammonium substituted epoxide, referred to in the industry (CTFA) as Polyquaternium 10. Another type of cationic cellulose includes the polymeric quaternary ammonium salts of hydroxyethyl cellulose reacted with lauryl dimethyl ammonium-substituted epoxide, 15 referred to in the industry (CTFA) as Polyquaternium 24. These materials are available from Amerchol Corp. (Edison, N.J., USA) under the tradename Polymer LM-200.

A particularly suitable type of cationic polysaccharide polymer that can be used is a cationic guar gum derivative, such as guar hydroxypropyltrimonium chloride (Commercially available from Rhone-Poulenc in their JAGUAR trademark series). Examples are JAGUAR C13S, which has a low degree of substitution of the cationic groups and high viscosity, JAGUAR C15, having a moderate degree of substitution and a low viscosity, JAGUAR C17 (high degree of substitution, high viscosity), JAGUAR C16, which is a hydroxypropylated cationic guar derivative containing a low level of substituent groups as well as cationic quaternary ammonium groups, and JAGUAR 162 which is a high transparency, medium viscosity guar having a low degree of substitution. Particularly preferred cationic polymers are JAGUAR C13S, JAGUAR C15, JAGUAR C17 and JAGUAR C16 and JAGUAR C162, especially JAGUAR C13S, and JAGUAR C-14/BFG. The JAGUAR C14/BFG material is the same molecule as JAGUAR C13, except that a glyoxal cross linker has replaced the boron. Other cationic skin feel agents known in the art may be used provided that they are compatible with the inventive formulation.

Other suitable examples of surfactants described above which may be used are described in "Surface Active Agents and Detergents" (Vol. I & II) by Schwartz, Perry & Berch, incorporated into the subject application by reference in its entirety. In addition, the inventive cleansing composition of the invention may include 0 to 15% by wt. optional ingredients as follows: perfumes; sequestering agents, such as tetrasodium ethylenediaminetetraacetate (EDTA), EHDP or mixtures in an amount of 0.01 to 1 %, preferably 0.01 to 0.05%; and soluble coloring agents, and the like; all of which are useful in so enhancing the appearance or cosmetic properties of the product. The compositions may further comprise antimicrobials such as 2-hydroxy-4,2',4' trichlorodiphenylether (DP300); preservatives such as dimethyloldimethylhydantoin (Glydant 55 XL1000), parabens, sorbic acid etc., and the like. The compositions may also comprise coconut acyl monoor 2.5 diethanol amides as suds boosters, and strongly ionizing salts such as sodium chloride and sodium sulfate may also be used to advantage. Preferably strongly ionizing salts, otherwise known as electrolytes, will be present at less than 3, 2 or 1 % by wt. Antioxidants such as, for example, butylated hydroxytoluene (BHT) and the like may be used advantageously in amounts of about 0.01 % or higher if appropriate.

Emollients

The term "emollient" is defined as a substance which softens or improves the elasticity, appearance, and youthfulness of the skin (stratum corneum) by either increasing its water content, adding, or replacing lipids and other skin nutrients; or both, and keeps it soft by retarding the decrease of its water content. Moisturizers that also are Humectants such as polyhydric alcohols, e.g. glycerin and propylene glycol, and the like; and polyols such as the polyethylene glycols and the like may be used as hydrophilic emollients. Humectants are preferably used at levels as low as 1 , 3 or 5% by wt. and at levels as high as 6, 8 or 10% by wt.

Petrolatum is used in the invention, preferably at levels as low as 1 , 3 or 4% by wt. and at levels as high as 5, 6, 8, 12 or 16% by wt. Petrolatum is defined as a mixture of liquid hydrocarbons derived from petroleum having a melting point between 35 and 80 degrees C (as determined by ASTM D127-08, "Standard Test Method for Drop Melting Point of Petroleum Wax, including Petrolatum", ASTM International, West Conshohocken, Pa.) and a minimum viscosity of 10 Kps at 32 degrees C. Preferably it has a viscosity range of 10 to 35 Kps at 32 degrees C. More preferably the upper limit of viscosity is 25 or 50 Kps at 32 degrees C.

Other non-Petrolatum hydrophobic emollients are preferably present at total levels of less than about 1 .5, 1 .0, or 0.5% by wt. in the inventive composition and are more preferably absent from the composition. These hydrophobic emollients include but are not limited to the following:

(a) silicone oils and modifications thereof such as linear and cyclic

polydimethylsiloxanes; amino, alkyl, alkylaryl, and aryl silicone oils;

(b) fats and oils including natural fats and oils such as jojoba, soybean, sunflower, rice bran, avocado, almond, olive, sesame, persic, castor, coconut, mink oils; cacao fat; beef tallow, lard; hardened oils obtained by hydrogenating the aforementioned oils; and synthetic mono, di and triglycerides such as myristic acid glyceride and 2-ethylhexanoic acid glyceride;

(c) waxes such as carnauba, spermaceti, beeswax, lanolin, and derivatives thereof;

(d) hydrophobic and hydrophillic plant extracts;

(e) non-Petrolatum hydrocarbons such as polybutene, liquid paraffins,

microcrystalline wax, ceresin, squalene, pristan and mineral oil;

(f) higher fatty acids such as lauric, myristic, palmitic, stearic, behenic, oleic, linoleic, linolenic, lanolic, isostearic, arachidonic and poly unsaturated fatty acids (PUFA);

(g) higher alcohols such as lauryl, cetyl, stearyl, oleyl, behenyl, cholesterol and 2- hexydecanol alcohol;

(h) esters such as cetyl octanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristyl myristate, isopropyl palmitate, isopropyl adipate, butyl stearate, decyl oleate, cholesterol isostearate, glycerol monostearate, glycerol distearate, glycerol tristearate, alkyl lactate, alkyl citrate and alkyl tartrate;

(i) essential oils and extracts thereof such as mentha, jasmine, camphor, white cedar, bitter orange peel, ryu, turpentine, cinnamon, bergamot, citrus unshiu, calamus, pine, lavender, bay, clove, hiba, eucalyptus, lemon, starflower, thyme, peppermint, rose, sage, sesame, ginger, basil, juniper, lemon grass, rosemary, rosewood, avocado, grape, grapeseed, myrrh, cucumber, watercress, calendula, elder flower, geranium, linden blossom, amaranth, seaweed, ginko, ginseng, carrot, guarana, tea tree, jojoba, comfrey, oatmeal, cocoa, neroli, vanilla, green tea, penny royal, aloe vera, menthol, cineole, eugenol, citral, citronelle, borneol, linalool, geraniol, evening primrose, camphor, thymol, spirantol, penene, limonene and terpenoid oils;

(j) mixtures of any of the foregoing components, and the like.

Isotropic Micellar Phase Compositions

Preferably, the inventive cleansing composition possesses isotropic micellar phase microstructure. The rheological behavior of all surfactant solutions, including liquid cleansing solutions, is strongly dependent on the microstructure, i.e., the shape and concentration of micelles or other self-assembled structures in solution.

When there is sufficient surfactant to form micelles (concentrations above the critical micelle concentration or CMC), for example, spherical, cylindrical (rod-like or discoidal), spherocylindrical, or ellipsoidal micelles may form. As surfactant concentration increases, ordered liquid crystalline phases such as lamellar phase, hexagonal phase, cubic phase or L3 sponge phase may form. The non-isotropic hexagonal phase, consists of long cylindrical micelles arranged in a hexagonal lattice. In general, the microstructure of most personal care products consist of either an isotropic dispersion including spherical micelles; and rod micelles; or an ordered liquid crystalline phase such as a lamellar dispersion. As noted above, micelles may be spherical or rod-like. Formulations having spherical micelles tend to have a low viscosity and exhibit Newtonian shear behavior (i.e., viscosity stays constant as a function of shear rate; thus, if easy pouring of product is desired, the solution is less viscous. In these systems, the viscosity increases linearly with surfactant concentration. Rod micellar solutions are more viscous because movement of the longer micelles is restricted. At a critical shear rate, the micelles align and the solution becomes shear thinning. Addition of salts increases the size of the rod micelles thereof increasing zero shear viscosity (i.e., viscosity when sitting in bottle) which helps suspend particles but also increases critical shear rate (point at which product becomes shear thinning; higher critical shear rates means that the product is more difficult to pour).

One way of characterizing isotropic micellar dispersions (hereinafter "isotropic compositions") include cone and plate viscosity measurement as described below. The inventive isotropic composition has a viscosity in the range of about 500 to about 300,000 cps at 1/sec shear rate at 25 degrees C as measured by a cone and plate technique described below. Preferably the viscosity is in the range of about 1 ,000 to 20,000 cps at 25 degrees C. Polymeric Dispersion Stabilizing Agents

Water soluble or dispersible polymeric dispersion agents are included in the inventive composition. Suitable agents include carbohydrate gums such as cellulose gum, microcrystalline cellulose, cellulose gel, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethylcellulose, hydroxymethyl carboxymethyl cellulose, carrageenan, hydroxymethyl carboxypropyl cellulose, methyl cellulose, ethyl cellulose, guar gum, gum karaya, gum tragacanth, gum arabic, gum acacia, gum agar, xanthan gum and mixtures thereof. Preferred carbohydrate gums are Hydroxypropyl Methocellulose such as Methocel® 40- 100 and Methocel 40-202 (Dow Chemicals, Midland, Mich.), Sodium Hydroxypropyl starch phosphate such as Pure-Gel B990 (Grain Processing Corp., Muscatine, Iowa), and Xanthan Gum such as Keltrol CG (CPKelco, Atlanta, Ga.).

Suitable polymeric dispersion agents also include acrylate containing homo and copolymers such as the crosslinked poly acrylates available 2.5 under the CARBOPOL trade name, the hydrophobically modified cross linked polyacrylates available under the AQUA trade name, and the PEMULEN trade name (all sold by Lubrizol Company, Wickliffe, Ohio) and the alkali swellable acrylic latex polymers sold by Rohm and Haas (Philadelphia, Pa.) under the ARYSOL or ACULYN trade names Preferred acrylates are the Aqua SF-1® and Carbopol Ultrez 21® polymers.

Liquid Crystalline, Clay and Silica Structuring Agents

Structuring agent(s) that assist in the formation of liquid crystalline network structures such as a lamellar structure as discussed above and insoluble agents such as clays and silicas, that form or assist in forming colloidal or other networks in surfactant solutions, are present at less than 1 .5, 1 or 0.5% by wt. total concentration and preferably are not present in the inventive composition. Excluded liquid crystalline structuring agents include but are not limited to saturated C14 to C30 fatty alcohols, saturated C16 to C30 fatty alcohols containing from about 1 to about 5 moles of ethylene oxide, saturated C16 to C30 diols, saturated C16 to C30 monoglycerol ethers, saturated C16 to C30 hydroxy fatty acids, C14 to C30 hydroxylated and n on hydroxy I ated saturated fatty acids, C14 to C30 saturated ethoxylated fatty acids, amines and alcohols containing from about 1 to about 5 moles of ethylene oxide diols, C14 to C30 saturated glyceryl mono esters with a monoglyceride content of at least 40%, C14 to C30 saturated polyglycerol esters having from about 1 to about 3 alkyl group and from about 2 to about 3 saturated glycerol units, C14 to C30 glyceryl mono ethers, C14 to C30 sorbitan mono/diesters, C14 to C30 saturated ethoxylated sorbitan mono/diesters with about 1 to about 5 moles of ethylene oxide, C14 to C30 saturated methyl glucoside esters, C14 to C30 saturated sucrose mono/diesters, C14 to C30 saturated ethoxylated methyl glucoside esters with about 1 to about 5 moles of ethylene oxide, C14 to C30 saturated polyglucosides having an average of between 1 to 2 glucose units and mixtures thereof. The foregoing structuring agent(s) include those having an HLB of from about 1 to about 8 and having a melting point of at least about 45° C. Additional examples of comparative liquid crystalline structuring agents include but are not limited to stearic acid, palmitic acid, stearyl alcohol, cetyl alcohol, behenyl alcohol, stearic acid, palmitic acid, the polyethylene glycol ether of stearyl alcohol having an average of about 1 to about 5 ethylene oxide units, the polyethylene glycol ether of cetyl alcohol having an average of about 1 to about 5 ethylene oxide units, and mixtures thereof Also included are stearyl alcohol, cetyl alcohol, behenyl alcohol, the polyethylene glycol ether of stearyl alcohol having an average of about 2 ethylene oxide units (steareth-2), the polyethylene glycol ether of cetyl alcohol having an average of about 2 ethylene oxide units, and mixtures thereof.

Other comparative liquid crystalline structuring agents include but are not limited to crystalline, hydroxyl-containing stabilizers such as a hydroxyl-containing fatty acid, fatty ester or fatty soap water-insoluble wax-like substance or the like. For example, the crystalline, hydroxy containing stabilizer may be selected from the group consisting of:

(i) CH2(ORi)CH₂(OR2)CH₂(OR3)

Wherein Ri is -COR₄(CHOH)xR₅(CHOH)_yR4;

wherein

Ri is -C-R₄(CHOH)xR₅(CHOH)_yR₆;

R₄ is C₀-2o Alkyl

R₅ is C₀-2o Alkyl

Re is C₀-2o Alkyl

and wherein 1 <=x+y<=4;

wherein

R₇ is -R₄(CHOH)xR₅(CHOH)_yR₆

M is Na⁺, K⁺ or Mg⁺⁺, or H; and

iii) mixtures thereof;

Other comparative hydroxyl-containing stabilizers include io but are not limited to 12- hydroxystearic acid, 9,10-dihydroxystearic acid, tri-9,10-dihydroxystearin and tri-12- hydroxystearin (hydrogenated castor oil is mostly tri-12-hydroxystearin). Also included in this class of comparative structurants are C10 -C22 ethylene glycol fatty acid esters. As discussed above, clay, silica and other particle based comparative structuring agent(s) are present at less than 1.5, 1 or 0.5% by wt. and preferably are not present in the inventive composition. These agents include but are not limited to dispersed amorphous silica selected from the group consisting of fumed silica and precipitated silica and mixtures thereof. As used herein the term "dispersed amorphous silica" refers to small, finely divided non-crystalline silica having a mean agglomerate particle size of less than about 100 microns.

Other examples of comparative structurants include but are not limited to dispersed smectite clay including bentonite and hectorite and mixtures thereof. Bentonite is a colloidal aluminum clay sulfate. Hectorite is a clay containing sodium, magnesium, lithium, silicon, oxygen, hydrogen and fluorine.

Optional Active Agents

Advantageously, active agents other than conditioning agents such as emollients or moisturizers defined above may be added to the cleansing composition in a safe and effective amount during formulation to treat the skin during the use of the product provided that they do not exceed solubility limits whereby the reflectance increases beyond 80% in the cleansing composition. Suitable active ingredients include those that are soluble in the aqueous phase, in the Petrolatum phase or in both phases. Suitable active agents may be advantageously selected from antimicrobial and antifungal actives, vitamins, anti-acne actives; anti-wrinkle, anti-skin atrophy and skin repair actives; skin barrier repair actives; non-steroidal cosmetic soothing actives; artificial tanning agents and accelerators; skin lightening actives; sunscreen actives; sebum stimulators; sebum inhibitors; anti-oxidants; protease inhibitors; skin tightening agents; anti-itch ingredients; hair growth inhibitors; 5- alpha reductase inhibitors; desquamating enzyme enhancers; anti-glycation agents; topical anesthetics, or mixtures thereof; and the like. These active agents may be selected from water soluble active agents, oil soluble active agents, pharmaceutically acceptable salts and mixtures thereof.

Also useful in the compositions of the invention are ingredients selected from organic solvents (ethanol), other thickeners, sequestrants (EDTA), coloring agents, opacifiers, pearlisers (zinc stearate, T1O2), preservatives (for example Glydant, parabens), antioxidants (BHT) and mixtures thereof).

The term "active agent" as used herein, means personal care actives which can be used to deliver a benefit to the skin and/or hair and which generally are not used to confer a conditioning benefit, as is conferred by humectants and emollients previously described herein. The term "safe and effective amount" as used herein, means an amount of active agent high enough to modify the condition to be treated or to deliver the desired skin care benefit, but low enough to avoid serious side effects. The term "benefit," as used herein, means the therapeutic, prophylactic, and/or chronic benefits associated with treating a particular condition with one or more of the active agents described herein. What is a safe and effective amount of the active agent ingredient will vary with the specific active agent, the ability of the active to penetrate through the skin, the age, health condition, and skin condition of the user, and other like factors.

Preferably the composition of the present invention comprise from about 0.01 % to about 50%, more preferably from about 0.05% to about 25%, even more preferably 0.1 % to about 10%, and most preferably 0.1 % % to about 5%, by weight of the active agent component. Anti-acne actives can be effective in treating acne vulgaris, a chronic disorder of the pilosebaceous follicles. Nonlimiting examples of useful anti-acne actives include the keratolytics such as salicylic acid (o-hydroxybenzoic acid), derivatives of salicylic acid such as 5-octanoyl salicylic acid and 4 methoxysalicylic acid, and resorcinol; retinoids such as retinoic acid and its derivatives (e.g., cis and trans); sulfur-containing D and L amino acids and their derivatives and salts, particularly their N-acetyl derivatives, mixtures thereof and the like.

Antimicrobial and antifungal actives can be effective to prevent the proliferation and growth of bacteria and fungi. Nonlimiting examples of antimicrobial and antifungal actives include b-lactam drugs, quinolone drugs, ciprofloxacin, norfloxacin, tetracycline, erythromycin, amikacin, 2,4,4'- trichloro-2'-hydroxy diphenyl ether, 3,4,4'-trichlorobanilide, phenoxyethanol, triclosan; triclocarban; and mixtures thereof and the like. Anti-wrinkle, anti-skin atrophy and skin repair actives can be effective in replenishing or rejuvenating the epidermal layer. These actives generally provide these desirable skin care benefits by promoting or maintaining the natural process of desquamation.

Nonlimiting examples of antiwrinkle and anti-skin atrophy actives include vitamins, minerals, and skin nutrients such as milk, vitamins A, E, and K; vitamin alkyl esters, including vitamin C alkyl esters; magnesium, calcium, copper, zinc and other metallic components; retinoic acid and its derivatives (e.g., cis and trans); retinal; retinol; retinyl esters such as retinyl acetate, retinyl palmitate, and retinyl propionate; vitamin B3 compounds (such as niacinamide and nicotinic acid), alpha hydroxy acids, beta hydroxy acids, e.g. salicylic acid and derivatives thereof (such as 5-octanoyl salicylic acid, heptyloxy 4 salicylic acid, and 4-methoxy salicylic acid); mixtures thereof and the like.

Skin barrier repair actives are those skin care actives which can help repair and replenish the natural moisture barrier function of the epidermis. Nonlimiting examples of skin barrier repair actives include lipids such as cholesterol, ceramides, sucrose esters and pseudo- ceramides as described in European Patent Specification No. 556,957; ascorbic acid; biotin; biotin esters; phospholipids, mixtures thereof, and the like. Non-steroidal cosmetic soothing actives can be effective in preventing or treating inflammation of the skin. The soothing active enhances the skin appearance benefits of the present invention, e.g., such agents contribute to a more uniform and acceptable skin tone or color. Nonlimiting examples of cosmetic soothing agents include the following categories: propionic acid derivatives; acetic acid derivatives; fenamic acid derivatives; mixtures thereof and the like. Many of these cosmetic soothing actives are described in U.S. Pat. No. 4,985,459 to Sunshine et al., issued Jan. 15, 1991 , incorporated by reference herein in its entirety.

Artificial tanning actives can help in simulating a natural suntan by increasing melanin in the skin or by producing the appearance of increased melanin in the skin. Nonlimiting examples of artificial tanning agents and accelerators include dihydroxyacetone; tyrosine; tyrosine esters such as ethyl tyrosinate and glucose tyrosinate; mixtures thereof, and the like.

Skin lightening actives can actually decrease the amount of melanin in the skin or provide such an effect by other mechanisms. Nonlimiting examples of skin lightening actives useful herein include aloe extract, alpha-glyceryl-L-ascorbic acid, aminotyroxine, ammonium lactate, glycolic acid, hydroquinone, 4 hydroxyanisole, mixtures thereof, and the like.

Also useful herein are sunscreen actives. A wide variety of sunscreen agents are described in U.S. Pat. No. 5,087,445, to Haffey et al., issued Feb. 1 1 , 1992; U.S. Pat. No. 5,073,372, to Turner et al., issued 2.5 Dec. 17, 1991 ; U.S. Pat. No. 5,073, 371 , to Turner et al. issued Dec. 17, 1991 ; and Segarin, et al., at Chapter VIII, pages 189 et seq., of Cosmetics Science and Technology, all of which are incorporated herein by reference in their entirety. Nonlimiting examples of sunscreens which are useful in the compositions of the present invention are those selected from the group consisting of octyl methoxyl cinnamate (Parsol MCX) and butyl methoxy benzoylmethane (Parsol 1789), 2-ethylhexyl p- methoxycinnamate, 2-ethylhexyl N,N-dimethyl-p-aminobenzoate, p-aminobenzoic acid, 2- phenylbenzimidazole-5-sulfonic acid, oxybenzone, mixtures thereof, and the like. Sebum stimulators can increase the production of sebum by the sebaceous glands. Nonlimiting examples of sebum stimulating actives include bryonolic acid, dehydroetiandro sterone (DHEA), orizanol, mixtures thereof, and the like.

Sebum inhibitors can decrease the production of sebum by the sebaceous glands. Nonlimiting examples of useful sebum inhibiting actives include aluminum hydroxy chloride, corticosteroids, dehydroacetic acid and its salts, dichlorophenyl imidazoldioxolan (available from Elubiol), mixtures thereof, and the like.

Also useful as actives in the present invention are protease inhibitors. Protease inhibitors can be divided into two general classes: the proteinases and the peptidases. Proteinases act on specific interior peptide bonds of proteins and peptidases act on peptide bonds adjacent to a free amino or carboxyl group on the end of a protein and thus cleave the protein from the outside. The protease inhibitors suitable for use in the present invention include, but are not limited to, proteinases such as serine proteases, metalloproteases, cysteine proteases, and aspartyl protease, and peptidases, such as carboxypepidases, dipeptidases and aminopepidases, mixtures thereof and the like.

Other useful as active ingredients in the present invention are skin tightening agents. Nonlimiting examples of skin tightening agents which are useful in the compositions of the present invention include monomers which can bind a polymer to the skin such as terpolymers of vinylpyrrolidone, (meth)acrylic acid and a hydrophobic monomer comprised of long chain alkyl (meth)acrylates, mixtures thereof, and the like. Active ingredients in the present invention may also so include anti-itch ingredients. Suitable examples of anti-itch ingredients which are useful in the compositions of the present invention include hydrocortisone, methdilizine and trimeprazineare, mixtures thereof, and the like.

Nonlimiting examples of hair growth inhibitors which are useful in the compositions of the present invention include beta estradiol, anti angiogenic steroids, curcuma extract, cycloxygenase inhibitors, evening primrose oil, linoleic acid and the like. Suitable 5-alpha reductase inhibitors such as ethynylestradiol and genistine mixtures thereof, and the like.

Nonlimiting examples of desquamating enzyme enhancers which are useful in the compositions of the present invention include alanine, aspartic acid, N methyl serine, serine, trimethyl glycine, mixtures thereof, and the like.

A nonlimiting example of an anti-glycation agent which is useful in the compositions of the present invention would be Amadorine (available from Barnet Products Distributor), and the like.

Pearl escer

The compositions of the present invention preferably include a pearlescer to improve visual appearance and/or consumer appeal of the product. Most preferably the pearlescer is selected from mica, titanium dioxide, titanium dioxide coated mica ethylene glycol distearate (INCI glycol distearate) and mixtures thereof.

The aqueous cleansing composition

The aqueous cleansing compositions of the invention are generally aqueous, i.e. they have water or an aqueous solution or a lyotropic liquid crystalline phase as their major component.

Suitably, the aqueous cleansing composition will comprise from 50 to 98%, preferably from 60 to 92% water by weight based on the total weight of the composition. Unless otherwise indicated, ratios, percentages, parts, and the like, referred to herein, are by weight.

EXAMPLES

Example 1 : Polymer for use in the compositions of the invention.

An anti-settling thickening polymer for use in these examples is prepared as follows:

A 3 liter, 4 necked round bottom flask equipped with a mechanical stirrer, thermocouple, condenser and nitrogen sparge is charged with 430 g of deionized water and 4.7 g of sodium lauryl sulfate. The flask is then purged with nitrogen and its contents are warmed to 90 °C. Then a first initiator solution containing 0.33 g of ammonium persulfate dissolved in 10 g of deionized water is added to the flask. Then a monomer solution is gradually charged to the flask over a period of 107 minutes, wherein the monomer solution contains 633 g deionized water, 18 g of sodium lauryl sulfate and the desired amounts of each of ethyl acrylate (EA), methacrylic acid (MAA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and a lipophilically modified monomer (LIPO) having the following structure:

wherein R¹ is a linear saturated C12-14 alkyl group; R² is selected from hydrogen or methyl; R² is selected from hydrogen or methyl, preferably methyl; and n is an average of 20 to 28. Starting simultaneously with the monomer solution charge, a second initiator solution containing 0.33 g of ammonium sulfate in 49 g of deionized water is gradually charged to the flask over a period of 1 12 minutes. Following the monomer charge and the second initiator solution charge, the transfer lines are rinsed with deionized waterfollowed by a free radical catalyst and activator chase solution. The resulting latex product is then recovered. Example 2: Preparation of bodywash and a liquid hand wash in accordance with the invention

A bodywash, in accordance with the invention may be prepared by the following method:

1 . Polymer is added to water.

2. The polymer is then allowed to swell by increasing the pH, using a suitable pH modifier, until a clear solution is obtained.

3. The cleansing surfactants, cationic polymer, fragrance and preservatives are then added to the swollen polymer and fully dispersed.

4. The resulting formulation is adjusted to the desired pH and viscosity using suitable pH and viscosity modifiers.

Composition of a body wash is shown in Table 2 below.

Table 2: Compositions of a body wash in accordance with the invention

Example 3: Preparation of bodvwashes, Compositions 1 -3, in accordance with the invention and Comprarative Compositions A-C

Body wash compositions were prepared, in accordance with the invention (designated Composition 1 - 3) which comprised the polymer shown in Table 3 below. Comparative Compositions, designated A - C were also made, which comprised polymers typically known in the prior art. The compositions are given in Tables 4 - 6.

The compositions were prepared using the method given in Example 2.

The details of the Polymer used in the compositions of the invention are given in Table 3 below, where the amount of AMPS is expressed over and above the combination of the other ingredients, in line with convention. The polymer was prepared as described in Example 1.

Table 3: Structural composition of polymer used in Compositions 1 - 3

Hydrophobe

Chain Length (n)

Ethyl

Hydrophobe when conforming Methacrylic AMPS

Polymer Acrylate

% to the structure acid % %

%

Polymer 16 13% 12, 3% 18 52.5 31.5 1

Table 4: Compositions of Bodywash 1 , in accordance with the invention and Comparative Bodywash A

^* Carbopol™ Aqua SF-1 , ex Lubrizol

pH's were in the range of from 6.5 to 7.0 as measured by calibrated pH meter.

Table 5: Compositions of Bodywash 2, in accordance with the invention and Comparative Bodywash B

^* Carbopol™ Aqua SF-1 , ex Lubrizol

pH's were in the range of from 5.3 to 5.5 as measured by calibrated pH meter.

Table 6: Compositions of Bodywash 3, in accordance with the invention and Comparative Bodywash C

arbopol™ C980 ex Lubrizol

pH's were in the range of from 6.8 to 7.2 as measured by calibrated pH meter.

Example 4: Silicone deposition, thermal storage stability and clarity of

Compositions 1 -3, in accordance with the invention and Comparative

Compositions A-C

The following analytical methods were used in these examples:

Silicone deposition:

Glass slides were treated with the test composition. The slides were rinsed and dried before the level of silicone was quantified. Thermal Stability:

Thermal stability was tested by placing the compositions in an oven at 45°C for 12 weeks. The compositions were assessed at regular time intervals over the 12 week period.

Transmission:

Transmission measurements were performed on the compositions using a Turbiscan or similar.

The results are summarised in the table below.

Table 7: Silicone deposition, thermal storage stability and clarity of Compositions

1 -3, in accordance with the invention and Comparative Compositions A-C

It will be seen that the compositions in accordance with the invention have superior silicone deposition, thermal storage stability and clarity compared with the comparatives.

Claims

1 . An aqueous skin cleansing composition, which comprises:

(II) a skin benefit agent,

(III) an anti-settling, thickening polymer,

wherein the anti-settling, thickening polymer, comprises:

(a) 40 to 74.5 wt% of structural units of C1-4 alkyl acrylate;

(b) 20 to 50 wt% of structural units of methacrylic acid;

(e) 0 to 1 wt% of structural units of acrylic acid; and

(f) 0 to 2 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer or chain transfer agent; and wherein the sum of the weight percentages of structural units (a)-(f) is equal to 100 wt% of the anti-settling, thickening polymer.

2. The aqueous composition as claimed in claim 1 , wherein the anti-settling, thickening polymer includes less than 0.001 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer; wherein the anti-settling, thickening polymer includes less than 0.1 wt% of structural units of chain transfer agent.

3. The aqueous composition as claimed in claim 1 or claim 2, wherein the anti-settling, thickening polymer has a weight average molecular weight of 25,000,000 to 300,000,000 Daltons.

4. The aqueous composition as claimed in any preceding claim, wherein the anti-settling, thickening polymer includes:

(a) 50 to 65 wt% of structural units of C1-4 alkyl acrylate, wherein the C1-4 alkyl acrylate is ethyl acrylate;

(b) 25 to 40 wt% of structural units of methacrylic acid;

(c) 0.75 to 2.0 wt% of structural units of 2-acrylamido-2-methylpropane sulfonic acid (AMPS);

(d) 10 to 20 wt% of structural units of the specialized associated monomer;

(e) 0 to 0.1 wt% of structural units of acrylic acid; and

(f) 0 to 0.001 wt% of structural units of multi-ethylenically unsaturated crosslinking monomer or chain transfer agent. 5. The aqueous composition as claimed in any preceding claim, which has a pH of 3.5 to 9.

5.

6. The aqueous composition as claimed in any preceding claim, wherein the skin benefit agent is present in an amount of from 0.01 wt% to 10 %wt of the total composition more preferably from 0.1 wt% to 5 wt%, most preferably 0.5 wt% to 3 wt%.

7. The aqueous composition as claimed in any preceding claim, wherein the cleansing surfactant is selected from the group consisting of sodium lauryl sulphate, sodium lauryl ether sulphate, sodium lauryl ether sulphosuccinate, ammonium lauryl sulphate, ammonium lauryl ether sulphate, sodium cocoyi isethionate, sodium cocoyi methyl taurate, sodium cocoyi glutamate, sodium cocoyi glycinate, and lauryl ether carboxylic acid, coco betaine, cocamidopropyl betaine, sodium cocoamphoacetate and mixtures thereof.

8. The aqueous composition as claimed in any preceding claim, wherein the cleansing surfactant is present in an amount of from 2 to 40 wt %.

9. The aqueous composition of as claimed in any preceding claim, which further comprises a pearlescer, preferably selected from the group consisiting of mica, titanium dioxide, titanium dioxide coated mica ethylene glycol distearate and mixtures thereof.

10. A method of treating skin comprising the step of applying to the skin a composition as defined by any of claims 1 to 9.

1 1 . A method as claimed in claim 10 which comprises the additional step of rinsing the skin with water.